Evaluation of Fatigue and Cutting Properties of Endodontic Rotary Instrument
| Autor: | Chi-Min Chang, 張棋閔 |
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| Rok vydání: | 2008 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 96 Endodontic rotary instruments subjected to tensile and compressive stress in canal may fracture without any warning. This research presented a systematic method to test fatigue properties of rotary instrument. An equipment has been established to test the fatigue lives of rotary instruments under different canal settings. A series of FEM analysis has been undertaken to evaluate the position and magnitude of the maximum principal strain in rotary instrument for the above settings. The maximum strain positions largely locate at 40%~60% bent length behind the tip of the instrument and are quite consistent with the fracture positions in the fatigue experiments. By combining the strain and the fatigue life data, we can have the S-N curve to represent the fatigue property of the rotary instrument. This study also established a method to evaluate cutting ability of rotary instrument. By comparing different types of rotary instruments, we discovered that the amount of cutting relates to the ratio of pitch length and diameter of rotary instrument. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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